# -*- coding: utf-8 -*-

# This program is free software: you can redistribute it and/or modify

# it under the terms of the GNU General Public License as published by

# the Free Software Foundation, either version 3 of the License, or

# (at your option) any later version.

#

# This program is distributed in the hope that it will be useful,

# but WITHOUT ANY WARRANTY; without even the implied warranty of

# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

# GNU General Public License for more details.

#

# You should have received a copy of the GNU General Public License

# along with this program.  If not, see <http://www.gnu.org/licenses/>.

"""

kallithea.lib.auth

~~~~~~~~~~~~~~~~~~

authentication and permission libraries

This file was forked by the Kallithea project in July 2014.

Original author and date, and relevant copyright and licensing information is below:

:created_on: Apr 4, 2010

:author: marcink

:copyright: (c) 2013 RhodeCode GmbH, and others.

:license: GPLv3, see LICENSE.md for more details.

"""

import os

import logging

import traceback

import hashlib

import itertools

import collections

from decorator import decorator

from tg import request, session

from tg.i18n import ugettext as _

from webhelpers.pylonslib import secure_form

from sqlalchemy.orm.exc import ObjectDeletedError

from sqlalchemy.orm import joinedload

from webob.exc import HTTPFound, HTTPBadRequest, HTTPForbidden, HTTPMethodNotAllowed

from kallithea import __platform__, is_windows, is_unix

from kallithea.config.routing import url

from kallithea.lib.vcs.utils.lazy import LazyProperty

from kallithea.model.meta import Session

from kallithea.model.user import UserModel

from kallithea.model.db import User, Repository, Permission, \

    UserToPerm, UserGroupRepoToPerm, UserGroupToPerm, UserGroupMember, \

    RepoGroup, UserGroupRepoGroupToPerm, UserIpMap, UserGroupUserGroupToPerm, \

    UserGroup, UserApiKeys

from kallithea.lib.utils2 import safe_str, safe_unicode, aslist

from kallithea.lib.utils import get_repo_slug, get_repo_group_slug, \

    get_user_group_slug, conditional_cache

from kallithea.lib.caching_query import FromCache

log = logging.getLogger(__name__)

class PasswordGenerator(object):

    """

    This is a simple class for generating password from different sets of

    characters

    usage::

        passwd_gen = PasswordGenerator()

        #print 8-letter password containing only big and small letters

            of alphabet

        passwd_gen.gen_password(8, passwd_gen.ALPHABETS_BIG_SMALL)

    """

    ALPHABETS_NUM = r'''1234567890'''

    ALPHABETS_SMALL = r'''qwertyuiopasdfghjklzxcvbnm'''

    ALPHABETS_BIG = r'''QWERTYUIOPASDFGHJKLZXCVBNM'''

    ALPHABETS_SPECIAL = r'''`-=[]\;',./~!@#$%^&*()_+{}|:"<>?'''

    ALPHABETS_FULL = ALPHABETS_BIG + ALPHABETS_SMALL \

        + ALPHABETS_NUM + ALPHABETS_SPECIAL

    ALPHABETS_ALPHANUM = ALPHABETS_BIG + ALPHABETS_SMALL + ALPHABETS_NUM

    ALPHABETS_BIG_SMALL = ALPHABETS_BIG + ALPHABETS_SMALL

    ALPHABETS_ALPHANUM_BIG = ALPHABETS_BIG + ALPHABETS_NUM

    ALPHABETS_ALPHANUM_SMALL = ALPHABETS_SMALL + ALPHABETS_NUM

    def gen_password(self, length, alphabet=ALPHABETS_FULL):

        assert len(alphabet) <= 256, alphabet

        l = []

        while len(l) < length:

            i = ord(os.urandom(1))

            if i < len(alphabet):

                l.append(alphabet[i])

        return ''.join(l)

def get_crypt_password(password):

    """

    Cryptographic function used for password hashing based on pybcrypt

    or Python's own OpenSSL wrapper on windows

    :param password: password to hash

    """

    if is_windows:

        return hashlib.sha256(password).hexdigest()

    elif is_unix:

        import bcrypt

        return bcrypt.hashpw(safe_str(password), bcrypt.gensalt(10))

    else:

        raise Exception('Unknown or unsupported platform %s'

                        % __platform__)

def check_password(password, hashed):

    """

    Checks matching password with it's hashed value, runs different

    implementation based on platform it runs on

    :param password: password

    :param hashed: password in hashed form

    """

    if is_windows:

        return hashlib.sha256(password).hexdigest() == hashed

    elif is_unix:

        import bcrypt

        try:

            return bcrypt.checkpw(safe_str(password), safe_str(hashed))

        except ValueError as e:

            # bcrypt will throw ValueError 'Invalid hashed_password salt' on all password errors

            log.error('error from bcrypt checking password: %s', e)

            return False

    else:

        raise Exception('Unknown or unsupported platform %s'

                        % __platform__)

def _cached_perms_data(user_id, user_is_admin, user_inherit_default_permissions,

                       explicit, algo):

    RK = 'repositories'

    GK = 'repositories_groups'

    UK = 'user_groups'

    GLOBAL = 'global'

    PERM_WEIGHTS = Permission.PERM_WEIGHTS

    permissions = {RK: {}, GK: {}, UK: {}, GLOBAL: set()}

    def _choose_perm(new_perm, cur_perm):

        new_perm_val = PERM_WEIGHTS[new_perm]

        cur_perm_val = PERM_WEIGHTS[cur_perm]

        if algo == 'higherwin':

            if new_perm_val > cur_perm_val:

                return new_perm

            return cur_perm

        elif algo == 'lowerwin':

            if new_perm_val < cur_perm_val:

                return new_perm

            return cur_perm

    #======================================================================

    # fetch default permissions

    #======================================================================

    default_user = User.get_by_username('default', cache=True)

    default_user_id = default_user.user_id

    default_repo_perms = Permission.get_default_perms(default_user_id)

    default_repo_groups_perms = Permission.get_default_group_perms(default_user_id)

    default_user_group_perms = Permission.get_default_user_group_perms(default_user_id)

    if user_is_admin:

        #==================================================================

        # admin users have all rights;

        # based on default permissions, just set everything to admin

        #==================================================================

        permissions[GLOBAL].add('hg.admin')

        permissions[GLOBAL].add('hg.create.write_on_repogroup.true')

        # repositories

        for perm in default_repo_perms:

            r_k = perm.UserRepoToPerm.repository.repo_name

            p = 'repository.admin'

            permissions[RK][r_k] = p

        # repository groups

        for perm in default_repo_groups_perms:

            rg_k = perm.UserRepoGroupToPerm.group.group_name

            p = 'group.admin'

            permissions[GK][rg_k] = p

        # user groups

        for perm in default_user_group_perms:

            u_k = perm.UserUserGroupToPerm.user_group.users_group_name

            p = 'usergroup.admin'

            permissions[UK][u_k] = p

        return permissions

    #==================================================================

    # SET DEFAULTS GLOBAL, REPOS, REPOSITORY GROUPS

    #==================================================================

    # default global permissions taken from the default user

    default_global_perms = UserToPerm.query() \

        .filter(UserToPerm.user_id == default_user_id) \

        .options(joinedload(UserToPerm.permission))

    for perm in default_global_perms:

        permissions[GLOBAL].add(perm.permission.permission_name)

    # defaults for repositories, taken from default user

    for perm in default_repo_perms:

        r_k = perm.UserRepoToPerm.repository.repo_name

        if perm.Repository.private and not (perm.Repository.owner_id == user_id):

            # disable defaults for private repos,

            p = 'repository.none'

        elif perm.Repository.owner_id == user_id:

            # set admin if owner

            p = 'repository.admin'

        else:

            p = perm.Permission.permission_name

        permissions[RK][r_k] = p

    # defaults for repository groups taken from default user permission

    # on given group

    for perm in default_repo_groups_perms:

        rg_k = perm.UserRepoGroupToPerm.group.group_name

        p = perm.Permission.permission_name

        permissions[GK][rg_k] = p

    # defaults for user groups taken from default user permission

    # on given user group

    for perm in default_user_group_perms:

        u_k = perm.UserUserGroupToPerm.user_group.users_group_name

        p = perm.Permission.permission_name

        permissions[UK][u_k] = p

    #======================================================================

    # !! OVERRIDE GLOBALS !! with user permissions if any found

    #======================================================================

    # those can be configured from groups or users explicitly

    _configurable = set([

        'hg.fork.none', 'hg.fork.repository',

        'hg.create.none', 'hg.create.repository',

        'hg.usergroup.create.false', 'hg.usergroup.create.true'

    ])

    # USER GROUPS comes first

    # user group global permissions

    user_perms_from_users_groups = Session().query(UserGroupToPerm) \

        .options(joinedload(UserGroupToPerm.permission)) \

        .join((UserGroupMember, UserGroupToPerm.users_group_id ==

               UserGroupMember.users_group_id)) \

        .filter(UserGroupMember.user_id == user_id) \

        .join((UserGroup, UserGroupMember.users_group_id ==

               UserGroup.users_group_id)) \

        .filter(UserGroup.users_group_active == True) \

        .order_by(UserGroupToPerm.users_group_id) \

        .all()

    # need to group here by groups since user can be in more than

    # one group

    _grouped = [[x, list(y)] for x, y in

                itertools.groupby(user_perms_from_users_groups,

                                  lambda x:x.users_group)]

    for gr, perms in _grouped:

        # since user can be in multiple groups iterate over them and

        # select the lowest permissions first (more explicit)

        # TODO: do this^^

        if not gr.inherit_default_permissions:

            # NEED TO IGNORE all configurable permissions and

            # replace them with explicitly set

            permissions[GLOBAL] = permissions[GLOBAL] \

                                            .difference(_configurable)

        for perm in perms:

            permissions[GLOBAL].add(perm.permission.permission_name)

    # user specific global permissions

    user_perms = Session().query(UserToPerm) \

            .options(joinedload(UserToPerm.permission)) \

            .filter(UserToPerm.user_id == user_id).all()

    if not user_inherit_default_permissions:

        # NEED TO IGNORE all configurable permissions and

        # replace them with explicitly set

        permissions[GLOBAL] = permissions[GLOBAL] \

                                        .difference(_configurable)

        for perm in user_perms:

            permissions[GLOBAL].add(perm.permission.permission_name)

    ## END GLOBAL PERMISSIONS

    #======================================================================

    # !! PERMISSIONS FOR REPOSITORIES !!

    #======================================================================

    #======================================================================

    # check if user is part of user groups for this repository and

    # fill in his permission from it. _choose_perm decides of which

    # permission should be selected based on selected method

    #======================================================================

    # user group for repositories permissions

    user_repo_perms_from_users_groups = \

     Session().query(UserGroupRepoToPerm, Permission, Repository,) \

        .join((Repository, UserGroupRepoToPerm.repository_id ==

               Repository.repo_id)) \

        .join((Permission, UserGroupRepoToPerm.permission_id ==

               Permission.permission_id)) \

        .join((UserGroup, UserGroupRepoToPerm.users_group_id ==

               UserGroup.users_group_id)) \

        .filter(UserGroup.users_group_active == True) \

        .join((UserGroupMember, UserGroupRepoToPerm.users_group_id ==

               UserGroupMember.users_group_id)) \

        .filter(UserGroupMember.user_id == user_id) \

        .all()

    multiple_counter = collections.defaultdict(int)

    for perm in user_repo_perms_from_users_groups:

        r_k = perm.UserGroupRepoToPerm.repository.repo_name

        multiple_counter[r_k] += 1

        p = perm.Permission.permission_name

        cur_perm = permissions[RK][r_k]

        if perm.Repository.owner_id == user_id:

            # set admin if owner

            p = 'repository.admin'

        else:

            if multiple_counter[r_k] > 1:

                p = _choose_perm(p, cur_perm)

        permissions[RK][r_k] = p

    # user explicit permissions for repositories, overrides any specified

    # by the group permission

    user_repo_perms = Permission.get_default_perms(user_id)

    for perm in user_repo_perms:

        r_k = perm.UserRepoToPerm.repository.repo_name

        cur_perm = permissions[RK][r_k]

        # set admin if owner

        if perm.Repository.owner_id == user_id:

            p = 'repository.admin'

        else:

            p = perm.Permission.permission_name

            if not explicit:

                p = _choose_perm(p, cur_perm)

        permissions[RK][r_k] = p

    #======================================================================

    # !! PERMISSIONS FOR REPOSITORY GROUPS !!

    #======================================================================

    #======================================================================

    # check if user is part of user groups for this repository groups and

    # fill in his permission from it. _choose_perm decides of which

    # permission should be selected based on selected method

    #======================================================================

    # user group for repo groups permissions

    user_repo_group_perms_from_users_groups = \

     Session().query(UserGroupRepoGroupToPerm, Permission, RepoGroup) \

     .join((RepoGroup, UserGroupRepoGroupToPerm.group_id == RepoGroup.group_id)) \

     .join((Permission, UserGroupRepoGroupToPerm.permission_id

            == Permission.permission_id)) \

     .join((UserGroup, UserGroupRepoGroupToPerm.users_group_id ==

            UserGroup.users_group_id)) \

     .filter(UserGroup.users_group_active == True) \

     .join((UserGroupMember, UserGroupRepoGroupToPerm.users_group_id

            == UserGroupMember.users_group_id)) \

     .filter(UserGroupMember.user_id == user_id) \

     .all()

    multiple_counter = collections.defaultdict(int)

    for perm in user_repo_group_perms_from_users_groups:

        g_k = perm.UserGroupRepoGroupToPerm.group.group_name

        multiple_counter[g_k] += 1

        p = perm.Permission.permission_name

        cur_perm = permissions[GK][g_k]

        if multiple_counter[g_k] > 1:

            p = _choose_perm(p, cur_perm)

        permissions[GK][g_k] = p

    # user explicit permissions for repository groups

    user_repo_groups_perms = Permission.get_default_group_perms(user_id)

    for perm in user_repo_groups_perms:

        rg_k = perm.UserRepoGroupToPerm.group.group_name

        p = perm.Permission.permission_name

        cur_perm = permissions[GK][rg_k]

        if not explicit:

            p = _choose_perm(p, cur_perm)

        permissions[GK][rg_k] = p

    #======================================================================

    # !! PERMISSIONS FOR USER GROUPS !!

    #======================================================================

    # user group for user group permissions

    user_group_user_groups_perms = \

     Session().query(UserGroupUserGroupToPerm, Permission, UserGroup) \

     .join((UserGroup, UserGroupUserGroupToPerm.target_user_group_id

            == UserGroup.users_group_id)) \

     .join((Permission, UserGroupUserGroupToPerm.permission_id

            == Permission.permission_id)) \

     .join((UserGroupMember, UserGroupUserGroupToPerm.user_group_id

            == UserGroupMember.users_group_id)) \

     .filter(UserGroupMember.user_id == user_id) \

     .join((UserGroup, UserGroupMember.users_group_id ==

            UserGroup.users_group_id), aliased=True, from_joinpoint=True) \

     .filter(UserGroup.users_group_active == True) \

     .all()

    multiple_counter = collections.defaultdict(int)

    for perm in user_group_user_groups_perms:

        g_k = perm.UserGroupUserGroupToPerm.target_user_group.users_group_name

        multiple_counter[g_k] += 1

        p = perm.Permission.permission_name

        cur_perm = permissions[UK][g_k]

        if multiple_counter[g_k] > 1:

            p = _choose_perm(p, cur_perm)

        permissions[UK][g_k] = p

    # user explicit permission for user groups

    user_user_groups_perms = Permission.get_default_user_group_perms(user_id)

    for perm in user_user_groups_perms:

        u_k = perm.UserUserGroupToPerm.user_group.users_group_name

        p = perm.Permission.permission_name

        cur_perm = permissions[UK][u_k]

        if not explicit:

            p = _choose_perm(p, cur_perm)

        permissions[UK][u_k] = p

    return permissions

def allowed_api_access(controller_name, whitelist=None, api_key=None):

    """

    Check if given controller_name is in whitelist API access

    """

    if not whitelist:

        from kallithea import CONFIG

        whitelist = aslist(CONFIG.get('api_access_controllers_whitelist'),

                           sep=',')

        log.debug('whitelist of API access is: %s', whitelist)

    api_access_valid = controller_name in whitelist

    if api_access_valid:

        log.debug('controller:%s is in API whitelist', controller_name)

    else:

        msg = 'controller: %s is *NOT* in API whitelist' % (controller_name)

        if api_key:

            # if we use API key and don't have access it's a warning

            log.warning(msg)

        else:

            log.debug(msg)

    return api_access_valid

class AuthUser(object):

    """

    Represents a Kallithea user, including various authentication and

    authorization information. Typically used to store the current user,

    but is also used as a generic user information data structure in

    parts of the code, e.g. user management.

    Constructed from a database `User` object, a user ID or cookie dict,

    it looks up the user (if needed) and copies all attributes to itself,

    adding various non-persistent data. If lookup fails but anonymous

    access to Kallithea is enabled, the default user is loaded instead.

    `AuthUser` does not by itself authenticate users and the constructor

    sets the `is_authenticated` field to False. It's up to other parts

    of the code to check e.g. if a supplied password is correct, and if

    so, set `is_authenticated` to True.

    However, `AuthUser` does refuse to load a user that is not `active`.

    Note that Kallithea distinguishes between the default user (an actual

    user in the database with username "default") and "no user" (no actual

    User object, AuthUser filled with blank values and username "None").

    If the default user is active, that will always be used instead of

    "no user". On the other hand, if the default user is disabled (and

    there is no login information), we instead get "no user"; this should

    only happen on the login page (as all other requests are redirected).

    `is_default_user` specifically checks if the AuthUser is the user named

    "default". Use `is_anonymous` to check for both "default" and "no user".

    """

    def __init__(self, user_id=None, dbuser=None, authenticating_api_key=None,

            is_external_auth=False):

        self.is_authenticated = False

        self.is_external_auth = is_external_auth

        self.authenticating_api_key = authenticating_api_key

        user_model = UserModel()

        self._default_user = User.get_default_user(cache=True)

        # These attributes will be overridden by fill_data, below, unless the

        # requested user cannot be found and the default anonymous user is

        # not enabled.

        self.user_id = None

        self.username = None

        self.api_key = None

        self.name = ''

        self.lastname = ''

        self.email = ''

        self.admin = False

        self.inherit_default_permissions = False

        # Look up database user, if necessary.

        if user_id is not None:

            log.debug('Auth User lookup by USER ID %s', user_id)

            dbuser = user_model.get(user_id)

        else:

            # Note: dbuser is allowed to be None.

            log.debug('Auth User lookup by database user %s', dbuser)